In panel test for spalling resistance, the average face temperature of panel assembly is maintained at __________ °C for 24 hours.
In panel test for spalling resistance, the average face temperature of panel assembly is maintained at __________ °C for 24 hours.
Chromite refractories are
Chromite refractories are
Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the
Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the
PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C.
PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C.
Conversion of silica mineral to cristobalite is accompanied by reduction in its
Conversion of silica mineral to cristobalite is accompanied by reduction in its
Hot metal runner in blast furnace are lined with __________ bricks.
Hot metal runner in blast furnace are lined with __________ bricks.
Chrome magnesite bricks are
Chrome magnesite bricks are
Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory
Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory
Zirconia refractories are not used in
Zirconia refractories are not used in
Maximum safe working temperature for fireclay bricks is about __________ °C.
Maximum safe working temperature for fireclay bricks is about __________ °C.
Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively.
Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively.
Fusion point of an acidic refractory material is
Fusion point of an acidic refractory material is
Bauxite calcining rotary kilns are lined with __________ bricks.
Bauxite calcining rotary kilns are lined with __________ bricks.
Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of
Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of
Magnesite bricks have poor resistance to attack by __________ slag.
Magnesite bricks have poor resistance to attack by __________ slag.
Magnesite chrome bricks are used in the
Magnesite chrome bricks are used in the
Addition of zircon to silica refractory brick improves its
Addition of zircon to silica refractory brick improves its
Which of the following bricks has the most close values of RUL and PCE?
Which of the following bricks has the most close values of RUL and PCE?
Test piece for determination of RUL of a refractory is heated in a/an
Test piece for determination of RUL of a refractory is heated in a/an
Cold crushing strength of ordinary fireclay brick is about 950 kg/cm² . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm² .
Cold crushing strength of ordinary fireclay brick is about 950 kg/cm² . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm² .
Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.
Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.
Lower wall courses of soaking pits are made of __________ bricks to avoid the action of molten slag & scale.
Lower wall courses of soaking pits are made of __________ bricks to avoid the action of molten slag & scale.
Roof of a basic electric furnace is made of __________ bricks.
Roof of a basic electric furnace is made of __________ bricks.
Which is the stable form of silica between 1470°C and the melting point 1713°C ?
Which is the stable form of silica between 1470°C and the melting point 1713°C ?
Which one contains maximum percentage of Al2O₃ ?
Which one contains maximum percentage of Al2O₃ ?
Maximum alumina content in high alumina refractory can be as high as __________ percent.
Maximum alumina content in high alumina refractory can be as high as __________ percent.
Fusion point of a basic refractory material is
Fusion point of a basic refractory material is
Insulating refractories should have
Insulating refractories should have
Presence of MgO in alumino-silicate refractories __________ its refractoriness.
Presence of MgO in alumino-silicate refractories __________ its refractoriness.
Which of the following is not a neutral refractory?
Which of the following is not a neutral refractory?
Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the
Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the
Roof of a basic open hearth furnace is lined with __________ bricks.
Roof of a basic open hearth furnace is lined with __________ bricks.
Thermal spalling mainly occurs during __________ of furnaces.
Thermal spalling mainly occurs during __________ of furnaces.
Which is required in an insulating refractory?
Which is required in an insulating refractory?
Thermal conductivity of refractory bricks
Thermal conductivity of refractory bricks
Which property of refractories is the most important for top section of the blast furnace?
Which property of refractories is the most important for top section of the blast furnace?
Magnesite refractories have low resistance to
Magnesite refractories have low resistance to
Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as __________ percent.
Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as __________ percent.
Hot blast main (carrying air at 1000°C) in blast furnace are lined with __________ bricks.
Hot blast main (carrying air at 1000°C) in blast furnace are lined with __________ bricks.
With increase in the alumina content in firebricks, its fusion point (refractoriness)
With increase in the alumina content in firebricks, its fusion point (refractoriness)
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Lower part of hot metal mixer are lined with __________ bricks.
Lower part of hot metal mixer are lined with __________ bricks.
Semi-silica bricks compared to silica bricks have
Semi-silica bricks compared to silica bricks have
Maximum water percentage in refractory mix meant for hand moulding may be as high as __________ percent.
Maximum water percentage in refractory mix meant for hand moulding may be as high as __________ percent.
__________ is the measure of the strength of refractory under the combined effect of temperature & load.
__________ is the measure of the strength of refractory under the combined effect of temperature & load.
High thermal conductivity of a refractory material is not important, when it is to be used in the
High thermal conductivity of a refractory material is not important, when it is to be used in the
Which brick undergoes maximum shrinkage on drying?
Which brick undergoes maximum shrinkage on drying?
Magnesite refractories are generally not used in the
Magnesite refractories are generally not used in the
Carbon refractory blocks
Carbon refractory blocks
Silica refractories are not used in
Silica refractories are not used in
Hot face insulating linings of high purity alumina fused mullite are used, where
Hot face insulating linings of high purity alumina fused mullite are used, where
Which of the following is not a high alumina refractory material?
Which of the following is not a high alumina refractory material?
High alumina refractories are used in the
High alumina refractories are used in the
Which is not a natural insulating material?
Which is not a natural insulating material?
Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material?
Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material?
Outer combustion chamber of blast furnace stove is lined with __________ bricks.
Outer combustion chamber of blast furnace stove is lined with __________ bricks.
Chemically, mullite refractories is
Chemically, mullite refractories is
Which is the stable form of silica below 870°C ?
Which is the stable form of silica below 870°C ?
Porosity of fireclay refractories is __________ percent.
Porosity of fireclay refractories is __________ percent.
Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as __________ percent.
Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as __________ percent.
__________ is not a single oxiderefractory.
__________ is not a single oxiderefractory.
Highest melting (m.p = 3070°C) oxide refractory is
Highest melting (m.p = 3070°C) oxide refractory is
Permeability of bricks is a measure of the
Permeability of bricks is a measure of the
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
__________ bricks should not be used in oxidising atmosphere.
__________ bricks should not be used in oxidising atmosphere.
Porosity of silica bricks varies from __________ percent.
Porosity of silica bricks varies from __________ percent.
Mixing of ground refractory material and water is done in a __________ mill.
Mixing of ground refractory material and water is done in a __________ mill.
Thermal diffusivity of a refractory brick is high, when its __________ is high.
Thermal diffusivity of a refractory brick is high, when its __________ is high.
Furnace atmosphere for softening temperature determination of refractories (in which segar cones are placed) should be
Furnace atmosphere for softening temperature determination of refractories (in which segar cones are placed) should be
Carbon bricks are not used in the lining of the
Carbon bricks are not used in the lining of the
Cold crushing strength of refractories depends upon its
Cold crushing strength of refractories depends upon its
Spalling resistance of a refractory can not be increased by
Spalling resistance of a refractory can not be increased by
Which is not a basic refractory?
Which is not a basic refractory?
Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for __________ bricks.
Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for __________ bricks.
Basic bricks are not made of
Basic bricks are not made of
Fireclay bricks is not used for lining the
Fireclay bricks is not used for lining the
Hollow refractory bricks are made by
Hollow refractory bricks are made by
Which is not an acidic refractory?
Which is not an acidic refractory?
An indication of degree of firing in silica brick is its
An indication of degree of firing in silica brick is its
Which of the following is not an acidic refractory?
Which of the following is not an acidic refractory?
Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C.
Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C.
Alumina-graphite bricks are used for lining the
Alumina-graphite bricks are used for lining the
Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves?
Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves?
Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity).
Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity).
Which is the stable form of silica upto 1470°C ?
Which is the stable form of silica upto 1470°C ?
Carbon refractories
Carbon refractories
__________ bricks are used in the burning zone of a cement rotary kiln.
__________ bricks are used in the burning zone of a cement rotary kiln.
An ideal refractory should have high
An ideal refractory should have high
Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with __________ bricks.
Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with __________ bricks.
Firing temperature of magnesite bricks is about __________ °C.
Firing temperature of magnesite bricks is about __________ °C.
Colour of fireclay bricks is
Colour of fireclay bricks is
Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called
Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called
Silica bricks are never used for lining the
Silica bricks are never used for lining the
Rotary kilns meant for calcination of limestone are lined with chrome magnesite in __________ zone.
Rotary kilns meant for calcination of limestone are lined with chrome magnesite in __________ zone.
Refractory bricks having lower porosity have
Refractory bricks having lower porosity have
Cold crushing strength of a refractory does not depend upon its
Cold crushing strength of a refractory does not depend upon its
Vacuum steel degassing units are lined with
Vacuum steel degassing units are lined with
Periclase refractory contains mainly
Periclase refractory contains mainly
Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of
Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of
